Beginning Python From Novice to Professional (8) － 文件方法

文件方法

读写：

#!/usr/bin/env python
f = open('somefile.txt','w')
f.write('Hello,')
f.write('World!')
f.close()
f = open('somefile.txt','r')
print f.read(5)

Hello

使用基本文件方法：

#!/usr/bin/env python
f = open(r'somefile.txt')
print f.read()
f.close()
f = open(r'somefile.txt')
for i in range(3):
	print str(i) + ':' + f.readline()
f.close()
import pprint
pprint.pprint(open(r'somefile.txt').readlines())
f = open('somefile.txt','w')
f.write('we\nchange\nthis file!')
f.close()
f = open(r'somefile.txt')
print f.read()
f.close()
f = open(r'somefile.txt')
lines = f.readlines()
f.close()
lines[1] = "changed\n"
f = open(r'somefile.txt','w')
f.writelines(lines)
f.close()
f = open(r'somefile.txt')
print f.read()
f.close()

This
is a
Test!

0:This

1:is a

2:Test!

['This\n', 'is a\n', 'Test!\n']
we
change
this file!
we
changed
this file!

文件解包：

#!/usr/bin/env python
f = open(r'somefile.txt','w')
f.write('First line\n')
f.write('Second line\n')
f.write('Third line\n')
f.close()
lines = list(open('somefile.txt'))
print lines
first,second,third = open('somefile.txt')
print first
print second
print third

['First line\n', 'Second line\n', 'Third line\n']
First line

Second line

Third line